pwm: Don't initialize list head before calling list_add()

list_add() just overwrites the members of the element to add (here:
chip->list) without any checks, even in the DEBUG_LIST case. So save the
effort to initialize the list.
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221117211143.3817381-5-u.kleine-koenig@pengutronix.deSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/core.c

@@ -299,7 +299,6 @@ int pwmchip_add(struct pwm_chip *chip)
 		radix_tree_insert(&pwm_tree, pwm->pwm, pwm);
 	}
 
-	INIT_LIST_HEAD(&chip->list);
 	list_add(&chip->list, &pwm_chips);
 
 	mutex_unlock(&pwm_lock);